In the related art, there is an apparatus for generating and distributing a clock signal, which includes multiple first LC resonance oscillators, each of which supplies a clock for each of multiple circuit blocks via a buffer, a second LC resonance oscillator with the same physical configuration as those of the multiple first LC resonance oscillators, a frequency divider that is connected to a feedback loop of the second LC resonance oscillator, a phase comparator, a charge pump, and a low-pass filter. A resistance element is inserted between oscillation nodes of the multiple first LC resonance oscillators and the second LC resonance oscillator.
Furthermore, there is an oscillator that includes at least two ring oscillation circuits, in each of which multiple inverters are connected to each other in multiple steps in the shape of a ring and conductive wiring, and in which an output from at least one inverter of all the ring oscillation circuits is connected to the conductive wiring.    Japanese Laid-open Patent Publication Nos. 2007-82158 and 11-74762 are examples of the related art, for example.